1. Field of the Invention
The present invention relates to a safety scanner and an optical safety system and, more particularly, to an improvement of a safety scanner and an optical safety system that receive reflected light from an object within a detection area to sense an intruder within a protection area.
2. Description of Related Art
An optical safety sensor is an area monitoring device which optically senses an intruder such as a person intruded into a protection area and outputs a safety control signal for emergently stopping a machine tool or an industrial robot (e.g., JP 2009-296087 A and JP 2009-294734 A).
For example, a safety scanner is an optical scanning area monitoring device provided with a light emitting part which emits detection light toward an object, a light receiving part which receives reflected light from the object and generates a light receiving signal, a distance calculation part which obtains a distance to the object on the basis of the light receiving signal, and a scanning part which causes the detection light to perform scanning in the circumferential direction around a rotation axis. Sensing of an intruder is performed by identifying the position of an object from the distance to the object and a scanning angle of the detection light and checking the identified position against a protection area.
Setting data which includes area designation information designating a protection area and measurement setting information designating a measurement condition are created using a setting support device. There is a conventional optical safety system that displays distance measurement information corresponding to the distance and the scanning angle on a screen as a scan image. The scan image is formed by two-dimensionally displaying a plurality of distance measurement information items obtained by performing scanning with detection light, and each of the distance measurement information items is indicated as a distance measurement position on a scanning plane of the detection light. Many distance measurement information items can be promptly grasped by displaying such a scan image.
However, it is not easy to grasp the correspondence relationship between the scan image and a real space, and it is not easy to grasp what in the real space a distance measurement position displayed on the scan image corresponds to. Even when the protection area is designated on such a scan image, it is difficult to determine whether or not the protection area is correctly designated at a desired position in the real space. Thus, for example, a conventional optical safety system requires an operation of actually checking whether or not an intruder is appropriately sensed after transferring setting data to the safety scanner, which disadvantageously makes an operation of creating setting data complicated.